Pressure bulb cap



3, 1954 w. B. KOCHNER 2,685,383

PRESSURE BULB CAP Filed Sept. 20, 1952 iumiiianr;

1527/672 for: William @Z mfinefl' Patented Aug. 3, 1954 PRESSURE BULB CAP William B. Kochner, St. Louis, Mo., assignor to Knapp-Monarch Company, St. Louis, Mo., a

corporation of Delaware Application September 20, 1952, Serial No. 310,711

1 Claim. 1

This invention relates to a pressure bulb cap and particularly one that is to be welded to the neck of the pressure bulb. Pressure bulbs of the character disclosed may be of the Sparklet type such as shown in Weida Patent No. 2,425,448, and Tomasek et al, Patent No. 2,481,042. The Weida patent shows a cup-like cap over the neck of a pressure bulb; whereas Figure 5a of the Tomasek et al. patent shows one which is adapted to rest on the upper end of the neck and be welded thereto. The type of cap shown in this figure is pressed from sheet metal, but sometimes these caps fail to hold the pressure because the sheet metal is sharply folded upon itself.

It is, therefore, an object of my present invention to improve on the type of pressure bulb cap disclosed in the Tomasek et al. patent by cold heading the cap or cold forging it, thus e1imi hating the folding of sheet metal and the sometimes resultant fracture thereof.

A further object of the present invention is to provide a cap which will be accurately centered in relation to the neck of the bulb so that a flange on the cap does not project to one side of the neck and interfere with introduction of the capped pressure bulb into a holder of a syphon or the like.

Still a further object is to provide a coldheaded or forged pressure bulb cap provided with a flange and projections formed thereon to raise the flange above the upper end of the neck of a bulb so that the bulb can be properly charged with CO2 or other gas when in a charging and Welding chamber of an apparatus for charging and sealing metallic bulbs of the character disclosed in the Tomasek at al. patent.

An additional object is to provide projections on the side wall of the pressure bulb cap to center it accurately in relation to the interior of the neck of the pressure bulb so as to avoid dislocation of the cap when the gas is being intro duced into the bulb.

With these and other objects in view, my invention consists in the construction, arrangement and combination of the various parts of my pressure bulb cap, whereby the objects contemplated are attained, as hereinafter more fully set forth, pointed out in my claim and illustrated in the accompanying drawings, wherein:

Figure 1 is a cross-sectional view through a pressure bulb and a charging and sealing head therefor with one of my pressure bulb caps mounted on the bulb during the charging operation.

Figure 2 is an enlarged sectional View of the neck of the bulb and a side elevation of my pressure bulb cap resting thereon.

Figure 3 is a similar view entirely in section showing the cap after it is welded in position.

Figure 4 is a horizontal detail sectional view on the line 44 of Figure 2.

Figure 5 is a bottom plan view of my pressure bulb cap; and

Figure 6 is a perspective view thereof with the cap inverted.

On the accompanying drawing I have used the reference character B to indicate in general a pressure bulb of the Sparklet type and H the head of a charging and sealing apparatus therefor. The charging and sealing apparatus is shown in detail in the Tomasek et al. patent hereinbefore referred to and includes a bulb seat element 24 and a sleeve 50 which has a coneshaped entrance bore 52 to guide the bulb into the sleeve and against an insert 5| therein of Bakelite or the like for sealing purposes. The sealing is accomplished with respect to a pressure chamber 28 to which pressure may be introduced through a passageway 26 from a passageway 3% in the head H.

Slidable in the head H is an electrode 22 adapted to subsequently be lowered against my pressure bulb cap shown generally at C. The bulb seat element 24 constitutes a second electrode so that when current is passed between 22 and 24, it will weld the cap C to the bulb B as shown in Figure 3.

The present invention relates particularly to the construction of the cap 0 which is adapted to enter the neck ll! of the bulb B and to also cover the neck. The cap C is inverted cup-shape having a relatively thin wall 12 adapted to be pierced by a piercing pin when the bulb is subsequently introduced into a syphon or the like. The cup is further defined by an annular wall l6 which is relatively thick, the dimensions being illustrated in Figure 3.

The cap C is formed by a cold-heading operation from wire stock of suitable size and the cold-heading or forging dies form the relatively thick wall [6 as well as the relatively thin wall I2. They also form a flange l4 around the wall [6 and in line with the wall I2 as illustrated and additionally form projections [8 on the flange l4 and projections 23 on the outside of the wall Hi.

When the cap C is placed in the neck In of the bulb B as shown in Figure 2, the projections l8 space the flange I4 from the upper end of the neck I!) as shown by the dimension indicated at 36 in Figure 2. At the same time the projections 20 space the annular wall I6 from the interior of the neck H3 equally all the way around the wall and neck as shown particularly in Figure 4. Thus the projections l8 and Z cooperate to provide passage for the charging gas from the passageway 26 through the pressure chamber 28 and into the bulb.

After the desired quantity of gas has been introduced into the bulb under pressure in this manner, the gas is cut off beyond the passageway 30 and the electrode 22 lowered into contact with the cap C. Electric current is then passed between the electrode 22 and the bulb seat 24 for heating the contacting parts (upper end of neck l and lower surfaces of projections 58) so that these contacting parts are heated and under further pressure and movement of the electrode 22 downwardly, the bottom of the flange ii finally engages the upper end of the neck 58 and a welding operation is effected between these two surfaces so that in effect the cap C and the bulb B become integral as indicated by the cross sectioning in Figure 3.

During the welding operation the projections 20 serve the further purpose of keeping the cap 0 centered in relation to the neck H! of the bulb B so that the periphery of the flange I i does not project at one point or another beyond the circumference of the neck. and thus interfere with the introduction of the bulb subsequently into a bulb holder.

From the foregoing specification, it will be obvious that I have provided a pressure bulb cap which is an improvement over the type shown in the Tomasek et al. patent. It is also an improvement over the Weida patent above referred to in that it does not enlarge the diameter of the neck it by having a side wall surrounding the neck. At the same time the construction is such that even though the bulb cap is of intricate shape, it is readily formed of suitable steel in cold-heading forming dies, without introducing any weak spots which might leak as disclosed in the type of cap shown in Figure 5a of the Tomasek et a1. patent.

Some changes may be made in the construction and arrangement of the parts of my pressure bulb cap without departing from the real 4 spirit and purpose of my invention, and it is my intention to cover by my claim any modified forms of structure or use of mechanical equivalents which may be reasonably included within its scope.

I claim as my invention:

In a welded fluid pressure bulb and cap struc ture, a container of resistance weldable metal having a tubular filling neck, and a closure cap of resistance weldable metal having a top wall of sufficient diameter to at least partially overlie the upper end of said neck, a solid sending tubular wall of substantiaily less external diameter than the internal diameter of said neck, said top wall, within the limits of the internal'diameter of said depen g tubular all, being thinner than the rei rider thereof to facilitate puncture thereof, and means to space the portion of said top wall overlying neck and the outer surface of said depend 1g tubuiar wall from the upper and inner s spectively of said neck comprising lee t three ribs on the under surface of said top wall and at least three ribs on the outer su tee of said depending tubular wail, said first l tively thick and narrow so that o spaces tween successive ribs and bettcon said neck and said upper wall provide free ilow of the fluid with which said container is to filled and said second ribs provide spaces etwecn said tubular wall and said neck to thereby permit ready entrance of such fluid into said while said closure cap is thereon prior to being welded thereto, first ribs, due to the relative narrowness thereof, being readily depressed into said neck and fused therewith upon welding said closure cap to said container and resulting in a continuous circular seal between the two.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,249,532 Smith et al Dec ii, 191? 2,184,939 Green Dec 1939 2,481,042 Tomasel: et a. Sept. 6, 1949 2,558,723 Ayres D July 3, 1951 

